7th Asia-Pacific Conference on Plasma Physics, 12-17 Nov, 2023 at Port Messe Nagoya

Multi-scale cooperative micro-motion and structural rearrangements in cold
dusty plasma liquids
Lin I, Hau-Wei Hu, and Yun-Xuan Zhang
Department of Physics and Center for Complex Systems, National Central University
e-mail: lini@phy.ncu.edu.tw

Counterintuitively, the micro-structure and motion in
the cold liquid around freezing are not completelydisordered. The interplay of the coherence generated by
the strong mutual interaction under the solid-like packing,and the disorder generated by the stochastic thermal
agitation slightly stronger than that in the solid, makes thecold liquid exhibit rich heterogeneous multiscale
structural and dynamical behaviors. For example, multiscale crystalline ordered domains (CODs) with different
lattice orientations could emerge, which facilitate orfrustrate thermal phonon excitation and propagation. It inturn induces avalanche-like cooperative particle hopping,structural rearrangement, and defect motion. Nevertheless,they are difficult to be directly visualized due to the small
atomic scale for liquids in nature.
The dusty plasma is composed of micro-meter sized
dust particles suspended in the low pressure gaseous
plasma background. The higher mobility of electrons thanthat of ions causes strong negative charging up to about
104 electrons per dust particle. Through tuning the strong
Coulomb coupling, the suspended dust particles can betuned from the gas to the solid state with proper spatial
and temporal scales (order of second relaxation time andsub-mm inter-particle spacing), which facilitate the direct
microscopic visualization of structure and motion throughdigital video microscopy [1-5]. It makes the dusty plasma
liquid a good platform to mimic and understand thegeneric micro-behaviors of the liquid at the kinetic level.
In this talk, our past works on the micro-behaviors of
the cold dusty plasma liquid around freezing will bebriefly reviewed [6-13], especially for: a) the emerging of
CODs with various lattice orientations and separated bymultiscale defect clusters, b) the stick-slip type particle
with alternative rattling in the cage formed by surrounding
particles and the avalanche-like cooperative hopping in
the form of multiscale clusters for inducing multi-scale
structural rearrangement and defect motion governed by
the conservation of Burgers vector, c) the thermallyinduced micro-acoustic wave (phonon) turbulence, andidentifying the alarm for avalanche structural
rearrangement through decomposing the multi-scalephonons, and d) the effect of supercooling andconfinement induced layering.

References:

1. J. H. Chu and Lin I, “Coulomb solid and low frequency
fluctuations in weakly ionized rf dusty plasmas”, J.
Phys. D. 27, 296 (1993).
2. J. H. Chu and Lin I, “Direct observation of Coulomb
lattice and liquid in strongly coupled dusty plasmas”,
Phys. Rev. Lett. 72, 4009 (1994).
3. Y. Hayashi and K. Tachibana, “Observation ofCoulomb crystal formation from carbon particlesgrown”, Jpn. J. Appl. Phys. 33, 804 (1994).
4.
H. Thomas, G. E. Morﬁll, V. Demmel, J. Goree, B.
Feuerbacher, and D. Mohmann, “Plasma crystal:
Coulomb crystallization in a dusty plasma”, Phys.
Rev. Lett. 73, 652 (1994).
5.
Lin I. W. T. Juan and C. H. Chiang, “Microscopicparticle motions in strongly coupled dusty plasmas”,
Science, 272, 162 (1996).
6. C. H. Chiang and Lin I, “Cooperative particle
motions and dynamical behaviors of free
dislocations in strongly coupled quasi-2D dustyplasmas” Phys. Rev. Lett. 77, 647 (1996).
7.
Y. J. Lai and Lin I, “Avalanche excitations of fast
particles in quasi-2d cold dusty plasma liquids”,
Phys. Rev. Letts. 89, 155002 (2002).
8.
C. Yang, C. W. Io and Lin I, “Cooperative motion
induced structural evolution in dusty plasma liquids
with micro-heterogeneity: rupture, rotation, healing,and growth of ordered domains”, Phys. Rev. Lett,109, 225003 (2012).
9.
H. W. Hu, W. Wang and Lin I, “Multiscale coherent
excitations in microscopic acoustic wave turbulenceof cold dusty plasma liquids”, Phys. Rev. Letts, 123,065002 (2019)
10. W. Wang, H. W. Hu, and Lin I, “Surface-inducedlayering of quenched 3D dusty plasma liquid: micromotion and structural rearrangement.”, Phys. Rev.
Letts, 124, 165001 (2020).
11. H. W. Hu, Y. X. Zhang, and Lin I, “Multiscalecooperative micro-excitations and structural
rearrangement in cold dusty plasma liquids”, Rev.
Modern Plasma Physics, 5, 13 (2021).
12. H. W. Hu, Y. C. Zhao, and Lin I, “Avalanche
structural rearrangements in cold dusty plasma
liquids through cascaded coherent excitations ofheterogeneous multiscale thermal acoustic waves”,
Phys. Rev. Research, 4, 23116 (2022).